Photosensitive resin composition and cured product thereof

ABSTRACT

Disclosed is a photosensitive resin composition comprising a resin (A) soluble in an aqueous alkaline solution, a crosslinking agent (B), a photopolymerization initiator (C) and a curing agent (D) wherein the curing agent (D) is an epoxy compound obtained by glycidylating a compound containing not less than 80% of a tetraphenylethane derivative represented by the following formula (1).  
                 
 
     In the formula, R 1  to R 8  independently represents a hydrogen atom, a C 1 -C 4  alkyl group or a halogen atom.

CROSS-REFERENCE TO PRIOR APPLICATION

This is a U.S. National Phase Application under 35 U.S.C. §371 ofInternational Patent Application No. PCT/JP2005/001817 filed Feb. 8,2005, and claims the benefit of Japanese Patent Application No.2004-031953, filed Feb. 9, 2004, both of which are incorporated byreference herein. The International Application was published inJapanese on Aug. 18, 2005 as WO 2005/076079 A1 under PCT Article 21(2).

TECHNICAL FIELD

The present invention relates to a photosensitive resin compositioncontaining, as a curing agent, a compound obtained by glycidylating atetraphenylethane derivative, and a cured product thereof. Moreparticularly, the invention relates to a liquid or dry-film type resincomposition which is useful as solder resists for printed wiring boards,interlayer insulating materials for multilayer printed wiring boards,solder resists for flexible printed wiring boards, dry-film resists,plating resists, materials for photosensitive optical waveguides, andthe like and which can give cured products excellent in developability,heat resistance, thermal stability, electrical insulation properties,adhesiveness, chemical resistance, plating resistance, and the like, anda cured product thereof.

BACKGROUND OF THE INVENTION

Photosensitive resin compositions containing photosensitive epoxycarboxylate compounds are excellent in balance between variousproperties, such as environmental, thermal, physical properties, andadhesiveness to substrates, and thus have been used in the fields ofpaint and coating, adhesives, and the like from a long time ago.Recently, the photosensitive resin compositions have been used widely inthe industrial applications, such as manufacturing of electrical andelectronic components, and manufacturing of printed boards, and therange of application thereof has been increasing. Furthermore, as theapplication field has expanded, there have been demands for addition ofhigher functions, such as heat resistance and adhesiveness, tophotosensitive resin compositions containing epoxy carboxylatecompounds, and development of various photosensitive resin compositionshas been in progress mainly in the applications, such as manufacturingof electrical and electronic components, and manufacturing of printedboards.

With respect to printed wiring boards, in view of decreases in size andweight of mobile devices and improvement in communication speed, highaccuracy and high density have been demanded. Accordingly, the levels ofrequirements for solder resists have been increasing, and there havebeen requirements for higher properties than before, that is,requirements for adhesiveness to substrate, high insulation properties,and resistance to electroless gold plating while maintaining higher heatresistance and thermal stability. However, in currently commerciallyavailable solder resists, these requirements are not satisfactorily met.For example, Patent Document 1 describes a solder mask compositioncontaining a photosensitive resin obtained by adding an acid anhydrideto a reaction product between a novolak epoxy resin and an unsaturatedmonobasic acid, a photopolymerization initiator, a crosslinking agent,and an epoxy resin. However, in the cured product of this composition,it is not possible to obtain satisfactory heat resistance, adhesiveness,and plating resistance. Furthermore, Patent Document 2 describes aphotopolymerizable resin composition containing a urethane-modifiedvinyl ester resin. However, in the cured product of this composition,although flexibility is obtained, it is not possible to obtainsatisfactory heat resistance and adhesiveness. Patent Documents 3, 4,and 5 each describes a high-purity compound obtained by glycidylating atetraphenylethane derivative, as a substance, and a synthesis methodthereof, but do not describe a photosensitive resin composition. PatentDocuments 6 and 7 each describe a compound obtained by glycidylating atetraphenylethane derivative as an example of a curing agent forphotosensitive resin compositions. However, the compound used has lowpurity, and in the photosensitive resin composition, it is not possibleto obtain satisfactory photosensitivity, developability, thermalstability, resolution, and heat resistance.

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 61-243869

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. 9-52925

Patent Document 3: Japanese Patent No. 3573530

Patent Document 4: Japanese Unexamined Patent Application PublicationNo. 9-3162

Patent Document 5: Japanese Unexamined Patent Application PublicationNo. 2004-10877

Patent Document 6: Japanese Unexamined Patent Application PublicationNo. 10-20493

Patent Document 7: Japanese Unexamined Patent Application PublicationNo. 2004-12810

SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

With respect to printed wiring boards, in view of decreases in size andweight of mobile devices and improvement in communication speed, highaccuracy and high density have been demanded. Accordingly, the levels ofrequirements for solder masks have been increasing, and there have beendemands for higher properties than before, that is, higher adhesiveness,resistance to soldering heat, and electroless gold plating resistance.However, in currently commercially available solder masks, these demandsare not satisfactorily met. It is an object of the present invention toprovide a resin composition which has excellent photosensitivity to anactivated energy ray, which allows a fine image suitable for higherfunctions of today's printed wiring boards to be formed, which enablespattern formation by means of development using a dilute aqueousalkaline solution, which is capable of producing a cured film havingsatisfactory heat resistance, the cured film being obtained by heatcuring in a post-cure step, and which is suitable for solder resist inkhaving high insulation properties, excellent adhesiveness, and excellentelectroless gold plating resistance; and a cured product thereof.

MEANS FOR SOLVING THE PROBLEMS

The present inventors have conducted intensive research to solve theproblems described above, and as a result, the present invention hasbeen completed.

That is, the present invention relates to:

1) a photosensitive resin composition containing a resin (A) soluble inan aqueous alkaline solution, a crosslinking agent (B), aphotopolymerization initiator (C), and a curing agent (D), wherein thecuring agent (D) is an epoxy compound obtained by glycidylating acompound containing not less than 80% of a tetraphenylethane derivativerepresented by formula

[wherein R₁ to R₈ each independently represents a hydrogen atom, a C₁ toC₄ alkyl group, or a halogen atom];

2) the photosensitive resin composition according to item 1), whereinthe epoxy compound, which is the curing agent (D), is a compoundobtained by glycidylating a tetraphenylethane derivative represented byformula (1), wherein each R₁ to R₈ is a hydrogen atom, and the compoundhas an epoxy equivalent of 120 to 200 g/equivalent;

3) the photosensitive resin composition according to item 1), whereinthe epoxy compound, which is the curing agent (D), includes a compoundrepresented by formula (2):

[wherein R₁ to R₈ each independently represents a hydrogen atom, a C₁ toC₄ alkyl group, or a halogen atom] and the content of the compound inthe curing agent (D) is not less than 60 mole percent;

4) the photosensitive resin composition according to any one of items 1)to 3), wherein the curing agent (D) has a softening point or meltingpoint of not less than 80° C.;

5) the photosensitive resin composition according to any one of items 1)to 3), wherein the curing agent (D) has a light transmittance at 400 nmof not less than 10% in a 1 weight percent methyl ethyl ketone solution;

6) the photosensitive resin composition according to any one of items 1)to 5), wherein the resin (A) soluble in the aqueous alkaline solution isa reaction product between an epoxy carboxylate compound obtained byreaction of an epoxy compound (a) having two or more epoxy groups permolecule with a monocarboxylic acid (b) having an ethylenic unsaturatedgroup per molecule, and a polybasic acid anhydride (c);

7) the photosensitive resin composition according to any one of items 1)to 5), wherein the resin (A) soluble in the aqueous alkaline solution isa reaction product between an epoxy carboxylate compound obtained byreaction of an epoxy compound (d) having two epoxy groups per moleculewith a monocarboxylic acid (b) having an ethylenic unsaturated group permolecule, a diisocyanate compound (e), a carboxylic acid (f) having twohydroxyl groups per molecule, and, as an optional component, a diolcompound (g);

8) a cured product of the photosensitive resin composition according toany one of items 1) to 7);

9) a substrate including a layer composed of the cured product accordingto item 8); and

10) an article including the substrate according to item 9).

ADVANTAGES

The photosensitive resin composition of the present invention isexcellent in tackiness, exhibits excellent photosensitivity in theformation of a cured product obtained by exposing the photosensitiveresin composition to an activated energy ray, such as ultraviolet light,enables pattern formation by means of development using a dilute aqueousalkaline solution, gives a cured product having satisfactoryadhesiveness, pencil hardness, solvent resistance, acid resistance, heatresistance, gold plating resistance, insulation properties, PCTresistance, thermal shock resistance, and the like, the cured productbeing obtained by heat curing in a post-cure step, and is particularlysuitable for solder resists for printed wiring boards. Thephotosensitive resin composition is also suitable for use in formingoptical waveguides.

DETAILED DESCRIPTION

A photosensitive resin composition of the present invention contains aresin (A) soluble in an aqueous alkaline solution, a crosslinking agent(B), a photopolymerization initiator (C), and a curing agent (D),wherein the curing agent (D) is an epoxy compound obtained byglycidylating a compound containing not less than 80% of atetraphenylethane derivative represented by the formula (1) describedabove [wherein R₁ to R₈ each independently represents a hydrogen atom, aC₁ to C₄ alkyl group, or a halogen atom].

The resin (A) soluble in the aqueous alkaline solution, which iscontained in the photosensitive resin composition of the presentinvention, is not particularly limited as long as it is soluble in anaqueous alkaline solution. In particular, the resin (A) soluble in theaqueous alkaline solution is preferably a reaction product between anepoxy carboxylate compound obtained by reaction of an epoxy compound (a)having two or more epoxy groups per molecule with a monocarboxylic acid(b) having an ethylenic unsaturated group per molecule, and a polybasicacid anhydride (c), or a reaction product between an epoxy carboxylatecompound obtained by reaction of an epoxy compound (d) having two epoxygroups per molecule with a monocarboxylic acid (b) having an ethylenicunsaturated group per molecule, a diisocyanate compound (e), acarboxylic acid (f) having two hydroxyl groups per molecule, and, as anoptional component, a diol compound (g).

As the epoxy compound (a) having two or more epoxy groups per molecule,in particular, an epoxy compound having an epoxy equivalent of 100 to900 g/equivalent is preferable. If the epoxy equivalent is less than 100g/equivalent, in some cases, the molecular weight of the resulting resin(A) soluble in the aqueous alkaline solution may be small, resulting indifficulty in forming a film, or sufficient flexibility may not beobtained. If the epoxy equivalent exceeds 900 g/equivalent, in thereaction with the monocarboxylic acid (b) having the ethylenicunsaturated group, there may be a possibility that its introductionratio decreases, resulting in a decrease in photosensitivity.

Specific examples of the epoxy compound (a) having two or more epoxygroups per molecule include a phenol novolak epoxy resin, a cresolnovolak epoxy resin, a tris(hydroxyphenyl)methane epoxy resin, adicyclo-pentadiene phenol-type epoxy resin, a bisphenol-A epoxy resin, abisphenol-F epoxy resin, a biphenol-type epoxy resin, a bisphenol-Anovolak epoxy resin, a naphthalene-skeleton-containing epoxy resin, analicyclic epoxy resin, and a heterocyclic epoxy resin.

Examples of the phenol novolak epoxy resin include EPICLON N-770(manufactured by Dainippon Ink and Chemicals, Inc.), D. E. N438(manufactured by Dow Chemical Company), EPIKOTE 154 (manufactured byYuka Shell Epoxy Co., Ltd.), and EPPN-201 and RE-306 (which aremanufactured by Nippon Kayaku Co., Ltd).

Examples of the cresol novolak epoxy resin include EPICLON N-695(manufactured by Dainippon Ink and Chemicals, Inc.), EOCN-102S,EOCN-103S, and EOCN-104S (all of which are manufactured by Nippon KayakuCo., Ltd.), UVR-6650 (manufactured by Union Carbide Corporation), andESCN-195 (manufactured by Sumitomo Chemical Co., Ltd).

Examples of the tris(hydroxyphenyl)methane epoxy resin include EPPN-503,EPPN-502H, and EPPN-501H (all of which are manufactured by Nippon KayakuCo., Ltd.), TACTIX-742 (manufactured by Dow Chemical Company), andEPIKOTE E1032H60 (manufactured by Yuka Shell Epoxy Co., Ltd).

Examples of the dicyclo-pentadiene phenol-type epoxy resin includeEPICLON EXA-7200 (manufactured by Dainippon Ink and Chemicals, Inc.) andTACTIX-556 (manufactured by Dow Chemical Company).

Examples of the bisphenol-type epoxy resin include bisphenol-A epoxyresins, such as EPIKOTE 828 and EPIKOTE 1001 (which are manufactured byYuka Shell Epoxy Co., Ltd.), UVR-6410 (manufactured by Union CarbideCorporation), D. E. R-331 (manufactured by Dow Chemical Company), andYD-8125 (manufactured by Tohto Kasei Co., Ltd.), and bisphenol-F epoxyresins, such as UVR-6490 (manufactured by Union Carbide Corporation) andYDF-8170 (manufactured by Tohto Kasei Co., Ltd).

Examples of the biphenol-type epoxy resin include biphenol epoxy resins,such as NC-3000 and NC-3000-H (which are manufactured by Nippon KayakuCo., Ltd.), bixylenol epoxy resins, such as YX-4000 (manufactured byYuka Shell Epoxy Co., Ltd.), and YL-6121 (manufactured by Yuka ShellEpoxy Co., Ltd).

Examples of the bisphenol-A novolak epoxy resin include EPICLON N-880(manufactured by Dainippon Ink and Chemicals, Inc.) and EPIKOTE E157S75(manufactured by Yuka Shell Epoxy Co., Ltd).

Examples of the naphthalene-skeleton-containing epoxy resin includeNC-7000 (manufactured by Nippon Kayaku Co., Ltd.) and EXA-4750manufactured by Dainippon Ink and Chemicals, Inc).

Examples of the alicyclic epoxy resin include EHPE-3150 (manufactured byDaicel Chemical Industries, Ltd).

Examples of the heterocyclic epoxy resin include TEPIC (manufactured byNissan Chemical Industries, Ltd).

Examples of the monocarboxylic acid (b) having the ethylenic unsaturatedgroup per molecule include acrylic acids, crotonic acid, α-cyanocinnamicacid, cinnamic acid, and a reaction product between a saturated orunsaturated dibasic acid and an unsaturated group-containingmonoglycidyl compound. Examples of acrylic acids include (meth)acrylicacid, β-styrylacrylic acid, β-furfurylacrylic acid, a half esterobtained by reaction between equimolar amounts of a saturated orunsaturated dibasic acid anhydride and a (meth)acrylate derivativehaving one hydroxyl group per molecule, a half ester obtained byreaction between equimolar amounts of a saturated or unsaturated dibasicacid and a monoglycidyl (meth)acrylate derivative, and a reactionproduct between (meth)acrylic acid and ε-caprolactone. In view ofsensitivity of the resulting photosensitive resin composition,(meth)acrylic acid, a reaction product between (meth)acrylic acid andε-caprolactone, or cinnamic acid is particularly preferable.

As the polybasic acid anhydride (c), any compound having at least oneacid anhydride structure per molecule can be used. Examples thereofinclude succinic anhydride, acetic anhydride, phthalic anhydride,pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride,hexahydrophthalic anhydride, ethylene glycol bis(anhydrotrimellitate),glycerol-bis(anhydrotrimellitate)monoacetate,1,2,3,4-butanetetracarboxylic dianhydride,3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride,3,3′,4,4′-benzophenonetetracarboxylic dianhydride,3,3′,4,4′-biphenyltetracarboxylic dianhydride,3,3′,4,4′-diphenylethertetracarboxylic dianhydride,2,2-bis(3,4-anhydrodicarboxyphenyl)propane,2,2-bis(3,4-anhydrodicarboxyphenyl)hexafluoropropane,5-(2,5-dioxotetrahydro-3-furanyl)-3-methylcyclohexene-1,2-dicarboxylicanhydride, and3a,4,5,9b-tetrahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione.

The preferable reaction product as the resin (A) soluble in the aqueousalkaline solution is obtained by subjecting an alcoholic hydroxylgroup-containing epoxy carboxylate compound produced by reaction(hereinafter referred to as a “first reaction”) of an epoxy compound (a)having two or more epoxy groups per molecule with a monocarboxylic acid(b) having an ethylenic unsaturated group per molecule to reaction(hereinafter referred to as a “second reaction”) with a polybasic acidanhydride (c).

The first reaction can be carried out in the absence of a solvent or ina solvent that does not contain an alcoholic hydroxyl group. Examplesthe solvent include ketones, such as acetone, ethyl methyl ketone, andcyclohexanone; aromatic hydrocarbons, such as benzene, toluene, xylene,and tetramethylbenzene; glycol ethers, such as ethylene glycol dimethylether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether,dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, andtriethylene glycol diethyl ether; esters, such as ethyl acetate, butylacetate, methyl cellosolve acetate, ethyl cellosolve acetate, butylcellosolve acetate, carbitol acetate, propylene glycol monomethyl etheracetate, dialkyl glutarates (e.g., dimethyl glutarate), dialkylsuccinates (e.g., dimethyl succinate), and dialkyl adipates (e.g.,dimethyl adipate); cyclic esters, such as y-butyrolactone; petroleumsolvents, such as petroleum ether, petroleum naphtha, hydrogenatedpetroleum naphtha, and solvent naphtha; and the crosslinking agent (B)which will be described below. These organic solvents may be used aloneor in combination of two or more.

With respect to the feed ratio of the starting materials in thisreaction, preferably, the amount of the monocarboxylic acid (b) havingthe ethylenic unsaturated group per molecule is 80 to 120 equivalentpercent relative to one equivalent of the epoxy compound (a). If theamount deviates from the range described above, there is a possibilitythat gelation may occur during the second reaction or the resultingresin (A) soluble in the aqueous alkaline solution may have decreasedthermal stability.

During the reaction, preferably, a catalyst is used to accelerate thereaction. When the catalyst is used, the amount of use thereof is 0.1%to 10% by weight relative to the reactants. In such a case, the reactiontemperature is 60° C. to 150° C., and the reaction time is preferably 5to 60 hours. Specific examples of the catalyst that may be used includetriethylamine, benzyldimethylamine, triethylammonium chloride,benzyltrimethylammonium bromide, benzyltrimethylammonium iodide,triphenylphosphine, triphenylstibine, methyltriphenylstibine, chromiumoctanoate, and zirconium octanoate.

Furthermore, preferably, as a thermal polymerization inhibitor,hydroquinone monomethyl ether, 2-methylhydroquinone, hydroquinone,diphenylpicrylhydrazine, diphenylamine, 2,6-di-tert-butyl-p-cresol, orthe like is used.

While performing sampling in an appropriate manner, the first reactionis terminated at a point where the acid value of the sample is 1mg·KOH/g or less, and preferably 0.5 mg·KOH/g or less.

In the present invention, the acid value of solid content is defined asan amount (mg) of potassium hydroxide required for neutralizing theacidity of carboxylic acid in 1 g of a resin, and the acid value isdefined as an amount (mg) of potassium hydroxide required forneutralizing 1 g of a solution including a resin. The acid value isdetermined by ordinary neutralization titration according to JIS K0070.Furthermore, if the concentration of a resin in a solution is known, itis also possible to calculate the acid value of solid content from theacid value of the solution.

The second reaction is an esterification reaction in which, after thetermination of the first reaction, a polybasic acid anhydride (c) isallowed to react with the reaction liquid. The second reaction can becarried out in the absence of a catalyst. Alternatively, in order toaccelerate the reaction, a basic catalyst can be used. When the catalystis used, the amount of use thereof is 10% by weight or less relative tothe reactants. In such a case, the reaction temperature is 40° C. to120° C., and the reaction time is preferably 5 to 60 hours.

With respect to the feed ratio of the polybasic acid anhydride (c),preferably, the amount of addition is calculated so that the acid valueof solid content of the resin (A) soluble in the aqueous alkalinesolution is 50 to 150 mg·KOH/g. If the acid value of solid content isless than 50 mg·KOH/g, solubility to the alkaline solution becomesinsufficient, and there is a possibility that residue may occur whenpatterning is performed, or in the worst case, it may not be possible toperform patterning. If the acid value of solid content exceeds 150mg·KOH/g, solubility to the alkaline solution becomes excessively high,and there is a possibility that the photo-cured pattern may be detached,thus being undesirable.

Although the epoxy compound (d) having two epoxy groups per moleculeused in the reaction to obtain a preferable reaction product as theresin (A) soluble in the aqueous alkaline solution is not particularlylimited, an epoxy compound having an epoxy equivalent of 100 to 900g/equivalent is preferable. If the epoxy equivalent is less than 100g/equivalent, in some cases, the molecular weight of the resulting resin(A) soluble in the aqueous alkaline solution may be small, resulting indifficulty in forming a film, or sufficient flexibility may not beobtained. If the epoxy equivalent exceeds 900 g/equivalent, in thereaction with the monocarboxylic acid (b) having the ethylenicunsaturated group, there may be a possibility that its introductionratio decreases, resulting in a decrease in photosensitivity.

In the present invention, the term “epoxy equivalent” is used in thesame meaning as in the ordinary use. The epoxy equivalent corresponds tothe mass of an epoxy compound containing 1 g equivalent of epoxy group,is represented in unit of g/equivalent, and is determined by a methodaccording to JIS K 7236, or the like.

Specific examples of the epoxy compound (d) having two epoxy groups permolecule include phenyl diglycidyl ethers, such as hydroquinonediglycidyl ether, catechol diglycidyl ether, and resorcinol diglycidylether; bisphenol-type epoxy compounds, such as bisphenol-A epoxy resins,bisphenol-F epoxy resins, bisphenol-S epoxy resins, and epoxy compoundsof 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane; hydrogenatedbisphenol-type epoxy compounds, such as hydrogenated bisphenol-A epoxyresins, hydrogenated bisphenol-F epoxy resins, hydrogenated bisphenol-Sepoxy resins, and epoxy compounds of hydrogenated2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane; halogenatedbisphenol-type epoxy compounds, such as brominated bisphenol-A epoxyresins and bisphenol-S epoxy resins; alicyclic diglycidyl ethercompounds, such as cyclohexanemethanol diglycidyl ether compounds;aliphatic diglycidyl ether compounds, such as 1,6-hexanediol diglycidylether, 1,4-butanediol diglycidyl ether, and diethylene glycol diglycidylether; polysulfide-type diglycidyl ether compounds, such as polysulfidediglycidyl ether; and biphenol-type epoxy resins.

With respect to these epoxy compounds, examples of the commerciallyavailable products include bisphenol-A epoxy resins, such as EPIKOTE828, EPIKOTE 1001, EPIKOTE 1002, EPIKOTE 1003, and EPIKOTE 1004 (all ofwhich are manufactured by Japan Epoxy Resin Co., Ltd.), EPOMIC R-140,EPOMIC R-301, and EPOMIC R-304 (all of which are manufactured by MitsuiChemicals, Inc.), DER-331, DER-332, and DER-324 (all of which aremanufactured by Dow Chemical Company), EPICLON 840 and EPICLON 850(which are manufactured by Dainippon Ink and Chemicals, Inc.), UVR-6410(manufactured by Union Carbide Corporation), RE-310S (manufactured byNippon Kayaku Co., Ltd.), and YD-8125 (manufactured by Tohto Kasei Co.,Ltd.); bisphenol-F epoxy resins, such as UVR-6490 (manufactured by UnionCarbide Corporation), YDF-2001, YDF-2004, and YDF-8170 (all of which aremanufactured by Tohto Kasei Co., Ltd.), and EPICLON 830 and EPICLON 835(which are manufactured by Dainippon Ink and Chemicals, Inc.);hydrogenated bisphenol-A epoxy resins, such as HBPA-DGE (manufactured byMaruzen Petrochemical Co., Ltd.) and Rika Resin HBE-100 (manufactured byShin-Nihon Kagaku Kogyo Co., Ltd.); brominated bisphenol-A epoxy resins,such as DER-513, DER-514, and DER-542 (all of which are manufactured byDow Chemical Company); alicyclic epoxy resins, such as Celoxide 2021(manufactured by Daicel Chemical Industries, Ltd.), Rika Resin DME-100(manufactured by Shin-Nihon Kagaku Kogyo Co., Ltd.), and EX-216(manufactured by Nagase Chemical Co., Ltd.); aliphatic diglycidyl ethercompounds, such as ED-503 (manufactured by ADEKA Corp.), Rika ResinW-100 (manufactured by New Japan Chemical Co., Ltd.), and EX-212,EX-214, and EX-850 (all of which are manufactured by Nagase ChemicalCo., Ltd.); polysulfide-type diglycidyl ether compounds, such as FLEP-50and FELP-60 (which are manufactured by Toray Thiokol Co., Ltd.); andbiphenol-type epoxy resins, such as YX-4000 (manufactured by Japan EpoxyResin Co., Ltd).

The diisocyanate compound (e) is not particularly limited as long as thecompound has two isocyanato groups per molecule, and also a plurality ofdiisocyanate compounds may be used. In particular, in view offlexibility and the like, specific examples of the preferreddiisocyanate compound (e) include phenylene diisocyanate, tolylenediisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate,diphenylmethane diisocyanate, naphthalene diisocyanate, tolidinediisocyanate, hexamethylene diisocyanate, dicyclohexylmethanediisocyanate, isophorone diisocyanate, arylene sulfone etherdiisocyanate, allylcyan diisocyanate, N-acyl diisocyanate,trimethylhexamethylene diisocyanate,1,3-bis(isocyanatomethyl)cyclohexane, and methylnorbornene-diisocyanate.

As the carboxylic acid (f) having two hydroxyl groups per molecule, anydiol compound having an alcoholic hydroxyl group or a phenolic hydroxylgroup and a carboxyl group per molecule can be used, and in particular,an alcoholic hydroxyl group which has excellent developability in anaqueous alkaline solution is preferable. Examples thereof includedimethylolpropionic acid and dimethylolbutanoic acid.

The diol compound (g) as the optional component is not particularlylimited as long as it is an aliphatic or alicyclic compound in which twohydroxyl groups are bonded to two different carbon atoms. Examplesthereof include ethylene glycol, propylene glycol, trimethylene glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol,1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, hydrobenzoin,benzpinacol, cyclopentane-1,2-diol, cyclohexane-1,2-diol,cyclohexane-1,4-diol, cyclohexane-1,2-dimethanol,cyclohexane-1,4-dimethanol, hydroxyl group-terminatedbutadiene-acrylonitrile copolymers, hydroxyl group-terminated spiroglycol, hydroxyl group-terminated dioxane glycol, hydroxylgroup-terminated tricyclodecane-dimethanol, hydroxyl group-terminatedmacromonomers containing polystyrene at the side chain, and hydroxylgroup-terminated macromonomers containing a polystyrene-acrylonitrilecopolymer at the side chain. The examples also include reaction productsbetween these diol compounds and oxides, such as ethylene oxide andpropylene oxide.

The preferable reaction product as the resin (A) soluble in the aqueousalkaline solution according to the present invention is obtained bysubjecting an alcoholic hydroxyl group-containing epoxy carboxylatecompound produced by reaction (hereinafter referred to as a “thirdreaction”) of an epoxy compound (d) having two epoxy groups per moleculewith a monocarboxylic acid (b) having an ethylenic unsaturated group permolecule to urethane reaction (hereinafter referred to as a “fourthreaction”) with a diisocyanate compound (e) and a carboxylic acid (f)having two hydroxyl groups per molecule. Here, a diol compound (g), asan optional component, may be added for reaction.

The third reaction can be carried out in the absence of a solvent or ina solvent that does not contain an alcoholic hydroxyl group. Examplesthe solvent include ketones, such as acetone, ethyl methyl ketone, andcyclohexanone; aromatic hydrocarbons, such as benzene, toluene, xylene,and tetramethylbenzene; glycol ethers, such as ethylene glycol dimethylether, ethylene glycol diethyl ether, dipropylene glycol dimethyl ether,dipropylene glycol diethyl ether, triethylene glycol dimethyl ether, andtriethylene glycol diethyl ether; esters, such as ethyl acetate, butylacetate, methyl cellosolve acetate, ethyl cellosolve acetate, butylcellosolve acetate, carbitol acetate, propylene glycol monomethyl etheracetate, dialkyl glutarates (e.g., dimethyl glutarate), dialkylsuccinates (e.g., dimethyl succinate), and dialkyl adipates (e.g.,dimethyl adipate); cyclic esters, such as y-butyrolactone; petroleumsolvents, such as petroleum ether, petroleum naphtha, hydrogenatedpetroleum naphtha, and solvent naphtha; and the crosslinking agent (B)which will be described below. These organic solvents may be used aloneor in combination of two or more.

With respect to the feed ratio of the starting materials in thisreaction, preferably, the amount of the monocarboxylic acid (b) havingthe ethylenic unsaturated group per molecule is 80 to 120 equivalentpercent relative to one equivalent of the epoxy compound (d). If theamount deviates from the range described above, there is a possibilitythat gelation may occur during the second reaction or the resultingresin (A) soluble in the aqueous alkaline solution may have decreasedthermal stability.

During the reaction, preferably, a catalyst is used to accelerate thereaction. When the catalyst is used, the amount of use thereof is 0.1%to 10% by weight relative to the reactants. In such a case, the reactiontemperature is 60° C. to 150° C., and the reaction time is preferably 5to 60 hours. Specific examples of the catalyst that may be used includetriethylamine, benzyldimethylamine, triethylammonium chloride,benzyltrimethylammonium bromide, benzyltrimethylammonium iodide,triphenylphosphine, triphenylstibine, methyltriphenylstibine, chromiumoctanoate, and zirconium octanoate.

Furthermore, preferably, as a thermal polymerization inhibitor,hydroquinone monomethyl ether, 2-methylhydroquinone, hydroquinone,2,6-di-tert-butyl-p-cresol, diphenylpicrylhydrazine, diphenylamine, orthe like is used.

While under performing sampling in an appropriate manner, the thirdreaction is terminated at a point where the acid value of the sample is1 mg·KOH/g or less, and preferably 0.5 mg·KOH/g or less.

The fourth reaction is a urethane reaction in which, after thetermination of the third reaction, a carboxylic acid (f) having twohydroxyl groups per molecule and a diol compound (g) as an optionalcomponent are added to the reaction liquid, and then a diisocyanatecompound (e) is gradually added thereto for reaction. The reaction canbe carried out in the absence of a catalyst. Alternatively, in order toaccelerate the reaction, a basic catalyst can be used. When the catalystis used, the amount of use thereof is 10% by weight or less relative tothe reactants. In such a case, the reaction temperature is 40° C. to120° C., and the reaction time is preferably 5 to 60 hours.

Furthermore, the solvent and the thermal polymerization inhibitor, suchas those described above, may also be used in this case.

While performing sampling in an appropriate manner, the fourth reactionis terminated at a point where absorption at around 2,250 cm⁻¹disappears in the infrared absorption spectrum of the sample.

With respect to the feed ratio of the carboxylic acid (f) having twohydroxyl groups per molecule, preferably, the amount of addition iscalculated so that the acid value of solid content of the resin (A)soluble in the aqueous alkaline solution is 50 to 150 mg·KOH/g. If theacid value of solid content is less than 50 mg·KOH/g, solubility to thealkaline solution becomes insufficient, and there is a possibility thatresidue may occur when patterning is performed, or in the worst case, itmay not be possible to perform patterning. If the acid value of solidcontent exceeds 150 mg·KOH/g, solubility to the alkaline solutionbecomes excessively high, and there is a possibility that thephoto-cured pattern may be detached, thus being undesirable.

With respect to the feed ratio of the diisocyanate compound (e),preferably, the amount of the diisocyanate compound (e) is set so thatthe ratio of (the number of moles of the epoxy carboxylate compoundproduced by the third reaction+the number of moles of the compound(f)+the number of moles of the diol compound (g) which is optionallyadded) to the number of moles of the compound (e) is in the range of 1to 5. If the ratio is less than 1, isocyanate remains at the end of theresulting resin (A) soluble in the aqueous alkaline solution. Thus,thermal stability is low, and there is a possibility that gelation mayoccur during storage, which is undesirable. If the ratio exceeds 5, themolecular weight of the resin (A) soluble in the aqueous alkalinesolution is decreased, and problems, such as tackiness and lowsensitivity, may occur.

When a solvent is used for the production of the resin (A) soluble inthe aqueous alkaline solution according to the present invention, theresin (A) soluble in the aqueous alkaline solution can be isolated byremoving the solvent by an appropriate method.

The amount of the resin (A) soluble in the aqueous alkaline solutionused in the photosensitive resin composition of the present invention isusually 15% to 70% by weight, and preferably 20% to 60% by weight, basedon 100% by weight of the solid content of the photosensitive resincomposition.

As the crosslinking agent (B) used in the photosensitive resincomposition of the present invention, a (meth)acrylate may be used.Specific examples thereof include 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, 1,4-butanediol mono(meth)acrylate,carbitol(meth)acrylate, acryloyl morpholine, half esters that arereaction products of hydroxyl group-containing (meth)acrylates (e.g.,2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, and1,4-butanediol mono(meth)acrylate) and acid anhydrides of polycarboxylicacids (e.g., succinic anhydride, maleic anhydride, phthalic anhydride,tetrahydrophthalic anhydride, and hexahydrophthalic anhydride),polyethylene glycol di(meth)acrylate, tripropylene glycoldi(meth)acrylate, trimethylolpropane tri(meth)acrylate,trimethylolpropanepolyethoxy tri(meth)acrylate, glycerol polypropoxytri(meth)acrylate, di(meth)acrylates of ε-caprolactone adduct of anester of hydroxy pivalate and neopentyl glycol (e.g., KAYARAD HX-220 andHX-620, manufactured by Nippon Kayaku Co., Ltd.), pentaerythritoltetra(meth)acrylate, poly(meth)acrylates of a reaction product ofdipentaerythritol and ε-caprolactone, dipentaerythritolpoly(meth)acrylate, and epoxy(meth)acrylates that are reaction productsof mono- or poly-glycidyl compounds (e.g., butylglycidyl ether,phenylglycidyl ether, polyethylene glycol diglycidyl ether,polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether,hexahydrophthalic diglycidyl ester, glycerol polyglycidyl ether,glycerol polyethoxy glycidyl ether, trimethylolpropane polyglycidylether, and trimethylolpropane polyethoxy polyglycidyl ether) and(meth)acrylic acid.

The amount of addition thereof is usually 2% to 40% by weight, andpreferably 5% to 30% by weight, based on 100% by weight of the solidcontent of the photosensitive resin composition.

Specific examples of the photopolymerization initiator (C) used in thephotosensitive resin composition of the present invention includebenzoins, such as benzoin, benzoin methyl ether, benzoin ethyl ether,benzoin isopropyl ether, and benzoin isobutyl ether; acetophenones, suchas acetophenone, 2,2-diethoxy-2-phenylacetophenone,1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one,diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one;anthraquinones, such as 2-ethylanthraquinone, 2-tert-butylanthraquinone,2-chloroanthraquinone, and 2-amylanthraquinone; thioxanthones, such as2,4-diethylthioxanthone, 2-isopropylthioxanthone, and2-chlorothioxanthone; ketals, such as acetophenone dimethyl ketal andbenzyl dimethyl ketal; benzophenones, such as benzophenone,4-benzoyl-4′-methyldiphenyl sulfide, and4,4′-bismethylaminobenzophenone; and phosphine oxides, such as2,4,6-trimethylbenzoyl diphenylphosphine oxide, andbis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. The amount of additionthereof is usually 1% to 30% by weight, and preferably 2% to 25% byweight, based on 100% by weight of the solid content of thephotosensitive resin composition.

These photopolymerization initiators (C) may be used alone or incombination of two or more. Furthermore, the photopolymerizationinitiator (C) can be used together with an accelerator or the like.Examples of the accelerator include tertiary amines, such astriethanolamine and methyldiethanolamine; and benzoic acid derivatives,such as ethyl N,N-dimethylaminobenzoate and isoamylN,N-dimethylaminobenzoate. The amount of addition of these acceleratorsis preferably 100% or less relative to the photopolymerization initiator(C).

The curing agent (D) used in the photosensitive resin composition of thepresent invention is an epoxy compound obtained by glycidylating acompound containing not less than 80% of a tetraphenylethane derivativerepresented by the formula (1) described above [wherein R₁ to R₈ eachindependently represents a hydrogen atom, a C₁ to C₄ alkyl group, or ahalogen atom]. In a resin coating film obtained by applying thephotosensitive resin composition, followed by photo-curing, theremaining carboxyl group and the epoxy group of the epoxy compound arereacted by heating, and thus a high-performance cured coating filmhaving strong chemical resistance and the like by means of the curingagent (D) can be obtained.

Specific examples of the C₁ to C₄ alkyl group in R₁ to R₈ in the formula(1) include a methyl group, an ethyl group, an n-propyl group, anisopropyl group, an n-butyl group, an s-butyl group, and a tert-butylgroup.

Examples of the halogen atom in R₁ to R₈ in the formula (1) include afluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The epoxy compound can be synthesized by a known method. That is, theepoxy compound can be obtained by glycidylating a tetraphenylethanederivative obtained by condensation of glyoxal with phenols.

Specific examples of phenols that is allowed to condense with glyoxalinclude unsubstituted phenols, such as phenol, resorcinol, andhydroquinone; substituted phenols, such as o-cresol, m-cresol, p-cresol,ethylphenol, n-propylphenol, isopropylphenol, tert-butylphenol,octylphenol, nonylphenol, phenylphenol, cyclohexylphenol, xylenol,methylpropylphenol, methylbutylphenol, allylphenol, and aminophenol; andhalogen atom-containing substituted phenols, such as brominated phenol.These phenols may be used alone or in combination of two or more. Whenthese phenols have positional isomers, all such isomers can be used inthe present invention. As phenols, phenol, o-cresol, m-cresol, andp-cresol are preferable, and phenol is particularly preferable.

As the tetraphenylethane derivative for producing the epoxy compound,which is the curing agent (D), contained in the photosensitive resincomposition of the present invention, a compound in which each R₁ to R₈is a hydrogen atom is preferable. As the commercially availabletetraphenylethane derivative, TEP-DF (manufactured by Asahi OrganicChemicals Industry Co., Ltd.) is desirable.

Glycidylation of the tetraphenylethane derivative will now be describedbelow.

After or while adding an alkali metal hydroxide to a mixture of thetetraphenylethane derivative and an excess amount of epihalohydrin,reaction is allowed to take place at 20° C. to 120° C. The alkali metalhydroxide may be used as an aqueous solution thereof. In such a case, amethod may be employed in which the aqueous solution of the alkali metalhydroxide is continuously added to the reaction mixture, water andepihalohydrin are continuously distilled under reduced pressure or undernormal pressure, the distillate is separated to remove water, andepihalohydrin is continuously returned to the reaction system.

Alternatively, a method may be employed in which an etherifiedhalohydrin compound is prepared by adding a quaternary ammonium salt,such as tetramethylammonium chloride, tetramethylammonium bromide, ortrimethylbenzylammonium chloride, to the tetraphenylethane derivativeand epihalohydrin, and allowing reaction to take place at 50° C. to 150°C.; then, a solid or an aqueous solution of an alkali metal hydroxide isadded to the etherified halohydrin compound, and reaction is allowed totake place at 20° C. to 120° C. to cause dehydrohalogenation (ringclosure).

In general, the amount of epihalohydrin used in such a reaction isusually 1 to 20 moles, and preferably 1.5 to 10 moles, relative to oneequivalent of the phenolic hydroxyl group of the tetraphenylethanederivative. The amount of use of the alkali metal hydroxide is 0.8 to1.5 moles, and preferably 0.9 to 1.1 moles, relative to one equivalentof the phenolic hydroxyl group of the tetraphenylethane derivative.Furthermore, in order to allow the reaction to proceed smoothly,preferably, an alcohol, such as methanol or ethanol, and an aproticpolar solvent, such as dimethyl sulfone or dimethyl sulfoxide, is addedto the reaction mixture.

When an alcohol is added, the amount of use thereof is preferably 2% to40% by weight, and particularly preferably 4% to 30% by weight, relativeto the amount of use of epihalohydrin. When an aprotic polar solvent isadded, the amount of use thereof is preferably 5% to 100% by weight, andparticularly preferably 10% to 90% by weight, relative to the amount ofuse of epihalohydrin.

After washing the reaction mixture of these glycidylation reactions withwater, or without water washing, epihalohydrin, the solvent, and thelike are removed under heating and reduced pressure. Thus, an epoxycompound can be obtained. Furthermore, by using a crystallization methodin which the epoxy compound is dissolved under heating in a solvent,such as methyl isobutyl ketone, followed by cooling, it is possible toobtain the epoxy compound as crystals.

As necessary, the following treatment may be performed, The resultingepoxy resin is dissolved in a hydrophobic solvent, an alkali metalhydroxide in an amount of 0.025 to 0.3 moles relative to one mole of thephenolic hydroxyl group of the tetraphenylethane derivative used as thestarting material is added to the solution, and stirring is performedpreferably at 40° C. to 90° C. for 30 minutes to 3 hours to performdehalogenation. In such a case, preferably, a 5 to 50 weight percentaqueous solution of the alkali metal hydroxide is used. Specificexamples of the hydrophobic solvent include methyl isobutyl ketone,benzene, toluene, and xylene. Methyl isobutyl ketone and toluene arepreferable. These solvents may be used alone or in combination. Afterthe reaction is completed, the resulting solution is washed with waterseveral times, and the hydrophobic solvent is distilled off underreduced pressure. Thus, a desired epoxy compound can be obtained.Furthermore, the epoxy compound can be obtained as crystals by the samecrystallization method as that described above.

The epoxy compound, which is the curing agent (D), may include acompound represented by the formula (2) [wherein R₁ to R₈ eachindependently represents a hydrogen atom, a C₁ to C₄ alkyl group, or ahalogen atom], and the content of the compound in the curing agent (D)is preferably not less than 60 mole percent, and more preferably notless than 80 mole percent.

The C₁ to C₄ alkyl group or the halogen atom is the same as thatdescribed with reference to the formula (1).

Other components contained in the curing agent (D) are compoundsproduced as by-products during the reaction between epihalohydrin andthe tetraphenylethane derivative, and like, which are mainly phenolichydroxyl group adducts of the epoxy group.

Furthermore, the epoxy compound, which is the curing agent (D), may be acompound obtained by glycidylating a compound containing not less than80% of a tetraphenylethane derivative wherein R₁ to R₈ are each ahydrogen atom, and the epoxy equivalent thereof is preferably in therange of 120 to 200 g/equivalent, and particularly preferably in therange of 155 to 180 g/equivalent.

The amount of addition of the curing agent (D) contained in thephotosensitive resin composition of the present invention is preferably200% or less of the equivalent calculated from the acid value of solidcontent and the amount of use of the resin (A) soluble in the aqueousalkaline solution contained in the photosensitive resin composition. Ifthe amount exceeds 200%, there is a possibility that developability maybe significantly degraded, which is undesirable.

Furthermore, preferably, the curing agent (D) contained in thephotosensitive resin composition of the present invention has asoftening point or melting point of not less than 80° C. In particular,the curing agent (D) preferably has a melting point of not less than100° C., and more preferably not less than 150° C.

Furthermore, the curing agent (D) contained in the photosensitive resincomposition of the present invention preferably has a lighttransmittance at 400 nm of not less than 10%, and particularlypreferably not less than 30%, in a 1 weight percent methyl ethyl ketonesolution. Examples of the commercially available epoxy resin include YDG414 (manufactured by Tohto Kasei Co., Ltd.) and EPIKOTE 1031S(manufactured by Japan Epoxy Resin Co., Ltd.), each of which has a veryhigh absorbance at 400 nm or less (i.e., a light transmittance of 0.0%in a 0.1 weight percent methyl ethyl ketone solution). In the case wherethese epoxy resins are used for the photosensitive resin composition,since the absorption maximum wavelength of the photopolymerizationinitiator (C) is usually 400 nm or less, the properties, such asdevelopability, of cured products of the photosensitive resincomposition are extremely poor.

The photosensitive resin composition of the present invention may befurther incorporated with various types of additives as required inorder to improve properties of the composition. Examples of suchadditives include fillers, such as talc, barium sulfate, calciumcarbonate, magnesium carbonate, barium titanate, aluminum hydroxide,aluminum oxide, silica, and clay; thixotropy imparting agents, such asAerosil; coloring agents, such as phthalocyanine blue, phthalocyaninegreen, and titanium oxide; silicone- or fluorine-based leveling agentsand antifoaming agents; and polymerization inhibitors, such ashydroquinone and hydroquinone monomethyl ether.

Although the curing agent (D) to be contained in the photosensitiveresin composition of the present invention may be mixed in advance inthe resin composition when used as a liquid resist, the curing agent (D)may be mixed before application to printed wiring boards. That is,preferably, a two-part system is formed in which a base solutionincluding the resin (A) soluble in the aqueous alkaline solution as themain component, and an epoxy-curing accelerator and the like addedthereto, and a curing agent solution including the curing agent (D) asthe main component are separately prepared, and these solutions aremixed immediately before use.

The photosensitive resin composition of the present invention contains aresin (A) soluble in an aqueous alkaline solution, a crosslinking agent(B), a photopolymerization initiator (C), and a curing agent (D).

The photosensitive resin composition of the present invention can beformed into a photosensitive layer, as necessary, by adding a filler,additives, and the like, and by sandwiching the photosensitive layerbetween a support film and a protective film, a dry film resist can beproduced. In such a case, the protective film is peeled off when used.After lamination on a substrate, exposure is performed, the supportingfilm is peeled off, and development is performed.

The photosensitive resin composition of the present invention is usefulas interlayer insulating materials for electronic components, opticalwaveguides that connect between optical components, solder resists forprinted wiring boards, and resist materials, such as cover lays. Inaddition, the photosensitive resin composition can also be used forcolor filters, printing ink, sealing materials, paint, coatingmaterials, adhesives, and the like.

A cured product of the photosensitive resin composition of the presentinvention is also covered by the present invention. The photosensitiveresin composition of the present invention is cured by irradiation of anenergy ray, such as ultraviolet light. The curing by irradiation of anenergy ray, such as ultraviolet light can be performed by an ordinarymethod. For example, when ultraviolet light is used, an ultravioletgenerator, such as a low-pressure mercury lamp, a high-pressure mercurylamp, an ultrahigh-pressure mercury lamp, a xenon lamp, or anultraviolet-light-emitting laser (e.g., an excimer laser), may be used.

The cured product of the resin composition of the present invention isused for electrical, electronic, and optical substrates, for example, asresist films, interlayer insulating materials used in a build-upprocess, and optical waveguides in printed wiring boards,photoelectronic substrates, and optical substrates, and these substratesare also covered by the present invention. The thickness of the layer ofthe cured product is about 0.5 to 160 μm, and preferably about 1 to 100μm.

Articles including these substrates are also covered by the presentinvention, and specific examples thereof include computers, homeelectric appliances, and mobile devices.

A printed wiring board including the photosensitive resin composition ofthe present invention can be obtained, for example, by the followingmethod. That is, when a liquid resin composition is used, thecomposition of the present invention is applied onto a substrate for aprinted wiring board by a process, such as screen-printing, spraying,roll-coating, electrostatic coating, or curtain-coating, at a thicknessof 5 to 160 μm, and drying is performed usually at 50° C. to 110° C.,and preferably at 60° C. to 100° C. A coating film is thereby formed.Subsequently, a high-energy ray, such as ultraviolet light, is appliedusually at an intensity of about 10 to 2,000 mJ/cm² directly orindirectly to the coating film through a photomask provided with anexposure pattern, such as a negative film. The unexposed portions aredeveloped with a developer, which will be described below, for example,by means of spraying, dipping under shaking, brushing, and scrubbing.Subsequently, as necessary, ultraviolet light is irradiated, and thenheat treatment is performed usually at 100° C. to 200° C., andpreferably at 140° C. to 180° C. Thus, a printed wiring board providedwith a permanent protective film that satisfies various properties, suchas heat resistance, solvent resistance, acid resistance, andadhesiveness, is obtained.

Examples of an aqueous alkaline solution used for the developmentdescribed above include aqueous inorganic alkaline solutions, such aspotassium hydroxide, sodium hydroxide, sodium carbonate, potassiumcarbonate, sodium bicarbonate, potassium bicarbonate, sodium phosphate,and potassium phosphate; and aqueous organic alkaline solutions, such astetramethylammonium hydroxide, tetraethylammonium hydroxide,tetrabutylammonium hydroxide, monoethanolamine, diethanolamine, andtriethanolamine.

The resin (A) soluble in the aqueous alkaline solution according to thepresent invention is soluble in an aqueous alkaline solution and is alsosoluble in the solvent described above. When used in solder resists,plating resists, and the like, it is possible to perform developmentusing the solvent.

EXAMPLES

While the present invention will be described in more detail based onexamples below, it is to be understood that the present invention is notlimited to the examples.

Synthesis Example 1

A 3-L flask equipped with an agitator and a reflux tube was charged with860.0 g of EOCN-103S manufactured by Nippon Kayaku Co., Ltd.(polyfunctional cresol novolak epoxy resin; epoxy equivalent: 215.0g/equivalent) as an epoxy compound (a) having two or more epoxy groupsper molecule, 288.3 g of acrylic acid (molecular weight: 72.06) as amonocarboxylic acid (b) having an ethylenic unsaturated group permolecule, 492.1 g of carbitol acetate as a reaction solvent, 4.921 g of2,6-di-tert-butyl-p-cresol as a thermal polymerization inhibitor, and4.921 g of triphenylphosphine as a reaction catalyst, and reaction wasallowed to take place at 98° C. until the reaction liquid had an acidvalue of 0.5 mg·KOH/g or less. Thereby, an epoxy carboxylate compoundwas obtained.

Subsequently, 169.8 g of carbitol acetate as a reaction solvent and201.6 g of tetrahydrophthalic anhydride as a polybasic acid anhydride(c) were added to the reaction liquid, and reaction was allowed to takeplace at 95° C. for 4 hours to obtain a resin solution (hereinafterreferred to as “A-1”) containing 67% by weight of a resin (A) soluble inan aqueous alkaline solution. The acid value was measured to be 69.4mg·KOH/g (acid value of solid content: 103.6 mg·KOH/g).

Synthesis Example 2

A 3-L flask equipped with an agitator and a reflux tube was charged with368.0 g of RE-310S manufactured by Nippon Kayaku Co., Ltd. (bifunctionalbisphenol-A epoxy resin; epoxy equivalent: 184.0 g/equivalent) as anepoxy compound (d) having two or more epoxy groups per molecule, 141.2 gof acrylic acid (molecular weight: 72.06) as a monocarboxylic acid (b)having an ethylenic unsaturated group per molecule, 1.02 g ofhydroquinone monomethyl ether as a thermal polymerization inhibitor, and1.53 g of triphenylphosphine as a reaction catalyst, and reaction wasallowed to take place at 98° C. until the reaction liquid had an acidvalue of 0.5 mg·KOH/g or less. Thereby, an epoxy carboxylate compound(theoretical molecular weight: 509.2) was obtained.

Subsequently, 755.5 g of carbitol acetate as a reaction solvent, 268.3 gof 2,2-bis(dimethylol)propionic acid (molecular weight: 134.16) as acarboxylic acid (f) having two hydroxyl groups per molecule, 1.08 g of2-methylhydroquinone as a thermal polymerization inhibitor, and 140.3 gof spiroglycol (molecular weight: 304.38) as a diol compound (g) as theoptional component were added to the reaction liquid, and thetemperature was increased to 45° C. Then, 485.2 g oftrimethylhexamethylene diisocyanate (molecular weight: 210.27) as adiisocyanate compound (e) was gradually added dropwise to the solutionsuch that the reaction temperature did not exceed 65° C. After thedropwise addition was completed, the temperature was increased to 80°C., and reaction was allowed to take place for 6 hours until absorptionat around 2,250 cm⁻¹ disappeared in infrared absorption spectrumanalysis. Thereby, a resin solution (hereinafter referred to as “A-2”)containing 65% by weight of a resin (A) soluble in an aqueous alkalinesolution according to the present invention was obtained. The acid valuewas measured to be 52.0 mg·KOH/g (acid value of solid content: 80.0mg·KOH/g).

Synthesis Example 3

Under nitrogen gas purge, 149 g of TEP-DF (manufactured by Asahi OrganicChemicals Industry Co., Ltd., 1,1,2,2-tetrakis(4-hydroxyphenyl)ethanecontent: 99%; measured at UV 254 nm by high performance liquidchromatography (HPLC)), 555 g of epichlorohydrin, and 111 g of methanolwere placed in a flask equipped with a thermometer, a cooling tube, andan agitator, and dissolution was performed. The solution was heated to70° C., 60 g of sodium hydroxide flake was added in portions theretoover 100 minutes, and then reaction was allowed to take place at 70° C.for 75 minutes. After the reaction was completed, excess epichlorohydrinand methanol were distilled off under reduced pressure of 5 mmHg at 130°C. using a rotary evaporator, and the residue was dissolved in 470 g ofmethyl isobutyl ketone.

The methyl isobutyl ketone solution was heated to 70° C., and 23 g ofmethanol and 10 g of a 30 weight percent aqueous sodium hydroxidesolution were added thereto. After reaction was allowed to take placefor 1 hour, water washing was repeated until the pH of the wash liquidbecame neutral. The aqueous layer was separated, and methyl isobutylketone was removed by distillation from the organic layer using a rotaryevaporator. Thereby, 219 g of an epoxy compound (D-1) in which the molarratio of 1,1,2,2-tetrakis(4-glycidyloxyphenyl)ethane was 74% (measuredby HPLC) was obtained. The epoxy equivalent was 170 g/equivalent. Themelt viscosity at 150° C. (measured by the cone-and-plate method at 150°C.; measuring apparatus: Cone & Plate (ICI) high-temperature viscometer(manufactured by RESEARCH EQUIPMENT (LONDON) LTD.), cone No.: 3(measurement range 0 to 2.00 Pa·s), amount of sample: 0.155±0.01 g) was0.4 poise. The softening point (measured according to JIS K-7234) was81.4° C.

Synthesis Example 4

Under nitrogen gas purge, 300 g of TEP-DF (manufactured by Asahi OrganicChemicals Industry Co., Ltd., 1,1,2,2-tetrakis(4-hydroxyphenyl)ethanecontent: 99%; measured at UV 254 nm by HPLC), 1,110 g ofepichlorohydrin, and 240 g of methanol were placed in a flask equippedwith a thermometer, a cooling tube, and an agitator, and dissolution wasperformed. The solution was heated to 70° C., 120 g of sodium hydroxideflake was added in portions thereto over 100 minutes, and then reactionwas allowed to take place at 70° C. for 60 minutes. After the reactionwas completed, washing was performed twice with 450 parts of water, andexcess epichlorohydrin and the like were distilled off from theresulting organic layer under heating and reduced pressure. The residuewas dissolved in 1,500 g of methyl isobutyl ketone under refluxconditions, and the solution was gradually cooled to 4° C. and left tostand for 24 hours. The resulting crystals were subjected to filtrationand drying, and thereby 294 g of a target epoxy compound (D-2) (epoxyequivalent: 165 g/equivalent, melting point: 174° C.,1,1,2,2-tetrakis(glycidyloxyphenyl)ethane content: 87 percent by area;measured by HPLC at UV 254 nm, light transmittance at 400 nm in a 1weight percent methyl ethyl ketone solution: ≧99%) was obtained ascolorless crystals.

Examples 1, 2, and 3

Using the curing agent (D-1) obtained in Synthesis Example 3 or thecuring agent (D-2) obtained in Synthesis Example 4, the resin solution(A-1) obtained in Synthesis Example 1 or the resin solution (A-2)obtained in Synthesis Example 2 and other components were mixed at themixing ratios shown in Table 1, and as necessary, kneaded with athree-roll mill. Thus, photosensitive resin compositions of the presentinvention were obtained. Each of these resin compositions was appliedonto a printed board by screen-printing such that the dry thickness was15 to 25 μm, and the coating film was dried at 80° C. with a hot-airdryer for 30 minutes. Subsequently, irradiation of ultraviolet light wasperformed, through a mask on which a circuit pattern had been drawn,with a UV exposure unit (manufactured by ORC Manufacturing Co., Ltd.,Model HMW-680GW). Then, spray development was performed using a 1 weightpercent aqueous sodium carbonate solution to remove the resin at theportions not irradiated with ultraviolet light. Water washing and dryingwere performed, and then the printed board was subjected to thermalcuring reaction at 150° C. for 60 minutes with a hot-air dryer. A curedfilm was thus obtained. The coating film was tested with respect totackiness, developability by performing development, and resolution, andthe resulting cured product was tested with respect to photosensitivity,surface gloss, adhesiveness, pencil hardness, solvent resistance, acidresistance, heat resistance, gold plating resistance, PCT resistance,and thermal shock resistance. The results thereof are shown in Table 2.The test methods and the evaluation methods are as follows.

(Tackiness) The coating film applied to the board after drying wasrubbed with absorbent cotton, and tackiness of the coating film wasevaluated.

◯ . . . Absorbent cotton did not stick.

× . . . Absorbent cotton waste stuck to the film.

(Developability) The following evaluation criteria were used.

◯ . . . During development, ink was completely removed and developmentwas performed completely.

× . . . During development, undeveloped portions occurred.

(Resolution) A negative pattern of 50 μm was brought into close contactwith the coating film after drying, and irradiation exposure wasperformed with ultraviolet light in an integrated amount of 200 mJ/cm².Subsequently, development was performed with a 1 weight percent aqueoussodium carbonate solution for 60 seconds at a spray pressure of 2.0kg/cm². The transferred pattern was observed with a microscope. Thefollowing criteria were used.

◯ . . . Resolved pattern had linear pattern edge.

× . . . Detachment occurred or pattern edge was irregular.

(Photosensitivity) A 21 step tablet (manufactured by Kodak Corp.) wasbrought into close contact with the coating film after drying, andirradiation exposure was performed with ultraviolet light in anintegrated amount of 500 mJ/cm². Subsequently, development was performedwith a 1 weight percent aqueous sodium carbonate solution for 60 secondsat a spray pressure of 2.0 kg/cm². The number of steps remaining withoutbeing developed was confirmed.

(Surface gloss) Irradiation exposure was performed with ultravioletlight in an amount of 500 mJ/cm². Subsequently, development wasperformed with a 1 weight percent aqueous sodium carbonate solution for60 seconds at a spray pressure of 2.0 kg/cm², and the cured film afterdrying was observed. The following criteria were used.

◯ . . . No haze was observed.

× . . . Slight haze was observed.

(Adhesiveness) According to JIS K5400, 100 squares (1 mm) were made on atest piece, and a peeling test was performed using a cellophane adhesivetape. The peeling state of the squares was observed, and evaluation wasperformed with the following criteria.

◯ . . . No peeling occurred.

× . . . Peeling occurred.

(Pencil hardness) Evaluation was performed according to JIS K5400.

(Solvent resistance) A test piece was dipped in isopropyl alcohol atroom temperature for 30 minutes. After checking whether or notabnormality occurred on the appearance, a peeling test was performedusing a cellophane adhesive tape, and evaluation was performed with thefollowing criteria.

◯ . . . No abnormality was observed on the appearance of the coatingfilm, and no blister or peeling was observed.

× . . . Blister and peeling were observed in the coating film.

(Acid resistance) A test piece was dipped in a 10% aqueous hydrochloricacid solution at room temperature for 30 minutes. After checking whetheror not abnormality occurred on the appearance, a peeling test wasperformed using a cellophane adhesive tape, and evaluation was performedwith the following criteria.

◯ . . . No abnormality was observed on the appearance of the coatingfilm, and no blister or peeling was observed.

× . . . Blister and peeling were observed in the coating film.

(Heat resistance) A rosin-based plux was applied to a test piece, andthe test piece was dipped in a solder bath at 260° C. for 5 seconds.This step was considered as one cycle, and three cycles were repeated.After the test piece was allowed to be cooled to room temperature, apeeling test was performed using a cellophane adhesive tape, andevaluation was performed with the following criteria.

◯ . . . No abnormality was observed on the appearance of the coatingfilm, and no blister or peeling was observed.

× . . . Blister and peeling were observed in the coating film.

(Gold plating resistance) A test substrate was dipped in an acidicdegreasing solution (20 volume percent aqueous solution of Metex L-5Bmanufactured by Nippon MacDermid Co., Ltd.) at 30° C. for 3 minutes,followed by washing with water. Subsequently, the test substrate wasdipped in a 14.4 weight percent aqueous ammonium persulfate solution for3 minutes, followed by washing with water. Furthermore, the testsubstrate was dipped in a 10 volume percent aqueous sulfuric acidsolution at room temperature for one minute, followed by washing withwater. Subsequently, the substrate was dipped in a catalyst solution (10volume percent aqueous solution of Metal Plate Activator 350manufactured by Meltex Inc.) at 30° C. for 7 minutes, followed bywashing with water, and then the substrate was subjected to nickelplating by dipping in a nickel plating solution (20 volume percentaqueous solution of Melplate Ni-865M, manufactured by Meltex Inc., pH4.6) at 85° C. for 20 minutes. Then, the test substrate was dipped in a10 volume percent aqueous sulfuric acid solution at room temperature forone minute, and washing with water was performed. Subsequently, the testsubstrate was subjected to electroless gold plating by dipping in a goldplating solution (an aqueous solution of 15 volume percent ofAurolectroless UP manufactured by Meltex Inc. and 3 volume percent ofgold potassium cyanide, pH 6) at 95° C. for 10 minutes, followed bywashing with water. Furthermore, the test substrate was dipped in hotwater at 60° C. for 3 minutes, followed by washing with water anddrying. A cellophane adhesive tape was applied to the resultingelectroless gold plated substrate for evaluation, and the state when theadhesive tape was peeled off was observed.

◯ . . . No abnormality was observed

× . . . Peeling was slightly observed.

(PCT resistance) A test substrate was left to stand in water at 121° C.and 2 atm for 96 hours. After checking whether or not abnormalityoccurred on the appearance, a peeling test was performed using acellophane adhesive tape, and evaluation was performed with thefollowing criteria.

◯ . . . No abnormality was observed on the appearance of the coatingfilm, and no blister or peeling was observed.

× . . . Blister and peeling were observed in the coating film.

(Thermal shock resistance) A test piece was subjected to thermalhysteresis of 1,000 cycles, one cycle including −55° C./30 minutes and125° C./30 minutes. Then, the test piece was observed with a microscope,and evaluation was performed with the following criteria.

◯ . . . No cracks occurred in the coating film

× . . . Cracks occurred in the coating film.

Comparative Examples 1 and 2

Photosensitive resin compositions for comparison were obtained by usingTEPIC manufactured by Nissan Chemical Industries, Ltd (ComparativeExample 1) or EPIKOTE 1031S manufactured by Japan Epoxy Resin Co., Ltd.(Comparative Example 2) instead of the curing agent used in Examples 1,2, and 3, and mixing at the mixing ratios shown in Table 1′. Cured filmswere obtained therefrom as in Examples. Tests were carried out as inExamples, and the results thereof are shown in Table 2. TABLE 1 ExampleRemarks 1 2 3 Resin solution A-1 51.80 51.80 A-2 51.80 Crosslinkingagent (B) DPHA *1 3.38 3.38 HX-220 *2 3.38 Photopolymerization initiator(C) Irgacure-907 *3 4.50 4.50 4.50 DETX-S *4 0.45 0.45 0.45 Curing agent(D) D-1 17.62 17.62 D-2 17.62 Thermal curing catalyst Melamine 1.00 1.001.00 Filler Barium sulfate 15.15 15.15 15.15 Phthalocyanine blue 0.450.45 0.45 Additive BYK-354 *7 0.39 0.39 0.39 KS-66 *8 0.39 0.39 0.39Solvent CA *9 4.87 4.87 4.87

TABLE 1′ Comparative Example Remarks 1 2 Resin solution A-1 51.80 51.80Crosslinking agent (B) DPHA *1 3.38 3.38 Photopolymerization initiator(C) Irgacure-907 *3 4.50 4.50 DETX-S *4 0.45 0.45 Curing agent (D) TEPIC*5 17.62 EPIKOTE1031S 17.62 Thermal curing catalyst Melamine 1.00 1.00Filler Barium sulfate 15.15 15.15 Phthalocyanine blue 0.45 0.45 AdditiveBYK-354 *7 0.39 0.39 KS-66 *8 0.39 0.39 Solvent CA *9 4.87 4.87Remarks*1 manufactured by Nippon Kayaku Co., Ltd.: dipentaerythritolpolyacrylate2 manufactured by Nippon Kayaku Co., Ltd.: ε-caprolactone-modifiedhydroxypivalic acid ester neopentyl glycol diacrylate*3 manufactured by Vantico Corp.:2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one

-   4 manufactured by Nippon Kayaku Co., Ltd.: 2,4-diethylthioxanthone-   5 manufactured by Nissan Chemical Industries, Ltd.: triglycidyl    isocyanurate-   6 manufactured by Japan Epoxy Resin Co., Ltd.: EPIKOTE 1031S-   7 manufactured by BYK-Chemie: leveling agent-   8 manufactured by Shin-etsu Chemical Ind.: antifoaming agent

9 carbitol acetate TABLE 2 Comparative Example Example Evaluation item 12 3 1 2 Tackiness ∘ ∘ ∘ ∘ x Developability ∘ ∘ ∘ ∘ x Resolution ∘ ∘ ∘ ∘x Photosensitivity 12 8 12 11 5 Surface gloss ∘ ∘ ∘ ∘ ∘ Adhesiveness ∘ ∘∘ ∘ x Pencil hardness 8H 4H 8H 7H 6H Solvent resistance ∘ ∘ ∘ x x Acidresistance ∘ ∘ ∘ x ∘ Heat resistance ∘ ∘ ∘ ∘ ∘ Gold plating ∘ ∘ ∘ ∘ ∘resistance PCT resistance ∘ ∘ ∘ x ∘ Thermal shock ∘ ∘ ∘ x ∘ resistance

As is evident from the results shown above, the photosensitive resincomposition of the present invention containing, as a curing agent, anepoxy compound obtained by glycidylating a compound represented byformula (1) and the cured product thereof are excellent particularly insolvent resistance, acid resistance, and PCT resistance. Furthermore,cracks do not occur in the surface of the cured product, and thephotosensitive resin composition of the present invention isparticularly useful as photosensitive resin composition for printedboards. On the other hand, in Comparative Example 2 in which EPIKOTE1013S, which is a commercially available epoxy compound, is used as acuring agent, tackiness, developability, resolution, and adhesivenessare inferior compared to the photosensitive resin composition of thepresent invention and the cured product thereof.

Example 3 Preparation of Dry Film

A resist resin composition was obtained by mixing 54.44 g of a resinwhich was prepared as in Synthesis Example 2 except that the solvent inthe solution (A-2) of the resin soluble in the aqueous alkaline solutionwas changed to propylene glycol monomethyl ether, 3.54 g of HX-220(trade name: diacrylate monomer manufactured by Nippon Kayaku Co., Ltd.)as a crosslinking agent (B), 4.72 g of Irgacure-907 (manufactured byCiba Specialty Chemicals) and 0.47 g of Kayacure-DETX-S (manufactured byNippon Kayaku Co., Ltd.) as photopolymerization initiators (C), 14.83 gof the compound (D-2) obtained in Synthesis Example 4 as a curingcomponent, 1.05 g of melamine as a thermal curing catalyst, and 20.95 gof methyl ethyl ketone as a concentration-regulating solvent, andkneading the mixture with a bead mill to achieve uniform dispersion.

The resulting composition was applied uniformly onto a poly(ethyleneterephthalate) film, i.e., a support film, by a roll-coating process,the film was transported through a hot-air drying furnace at 70° C., toform a resin layer with a thickness of 30 μm. Then, a polyethylene film,i.e., a protective film, was attached to the resin layer to prepare adry film. The resin layer of the resulting dry film was attached to theentire surface of a polyimide printed board (thickness of coppercircuit: 12 μm, thickness of polyimide film: 25 μm) using a hot rollerat 80° C. while peeling off the protective film. Subsequently, using aUV exposure unit (manufactured by ORC Manufacturing Co., Ltd., ModelHMW-680GW), irradiation of ultraviolet light was performed, through amask on which a circuit pattern had been drawn. Then, spray developmentwas performed using a 1 weight percent aqueous sodium carbonate solutionto remove the resin at the portions not irradiated with ultravioletlight. After washing with water, the printed board was subjected tothermal curing reaction with a hot-air dryer at 150° C. for 60 minutesto produce a cured film. With respect to the cured product, as in thetests described above, photosensitivity, surface gloss, adhesiveness,pencil hardness, solvent resistance, acid resistance, heat resistance,and gold plating resistance were tested. Substantially the same resultsas those shown in Example 2 of Table 2 were obtained.

As is evident from the results, the photosensitive resin composition ofthe present invention containing, as a curing agent, a compoundrepresented by formula (1) and the cured product thereof do not exhibittackiness and have excellent developability even if used as a dry film.The cured film thereof is also excellent in resistance to solderingheat, chemical resistance, gold plating resistance, and the like.Furthermore, cracks do not occur in the surface of the cured product,and the photosensitive resin composition of the present invention isexcellent as a photosensitive resin composition for printed boards.

1. A photosensitive resin composition comprising a resin (A) soluble inan aqueous alkaline solution, a crosslinking agent (B), aphotopolymerization initiator (C), and a curing agent (D), wherein thecuring agent (D) is an epoxy compound obtained by glycidylating acompound containing not less than 80% of a tetraphenylethane derivativerepresented by formula (1):

wherein R₁ to R₈ each independently represents a hydrogen atom, a C₁ toC₄ alkyl group, or a halogen atom.
 2. The photosensitive resincomposition according to claim 1, wherein the epoxy compound, which isthe curing agent (D), is a compound obtained by glycidylating atetraphenylethane derivative represented by formula (1) wherein each R₁to R₈ is a hydrogen atom, and the compound has an epoxy equivalent of120 to 200 g/equivalent.
 3. The photosensitive resin compositionaccording to claim 1, wherein the epoxy compound, which is the curingagent (D), includes a compound represented by formula (2):

wherein R₁ to R₈ each independently represents a hydrogen atom, a C₁ toC₄ alkyl group, or a halogen atom and the content of the compound in thecuring agent (D) is not less than 60 mole percent.
 4. The photosensitiveresin composition according to claim 1, wherein the curing agent (D) hasa softening point or melting point of not less than 80° C.
 5. Thephotosensitive resin composition according to claim 1, wherein thecuring agent (D) has a light transmittance at 400 nm of not less than10% in a 1 weight percent methyl ethyl ketone solution.
 6. Thephotosensitive resin composition according to claim 1, wherein the resin(A) soluble in the aqueous alkaline solution is a reaction productbetween an epoxy carboxylate compound obtained by reaction of an epoxycompound (a) having two or more epoxy groups per molecule with amonocarboxylic acid (b) having an ethylenic unsaturated group permolecule, and a polybasic acid anhydride (c).
 7. The photosensitiveresin composition according to claim 1, wherein the resin (A) soluble inthe aqueous alkaline solution is a reaction product between an epoxycarboxylate compound obtained by reaction of an epoxy compound (d)having two epoxy groups per molecule with a monocarboxylic acid (b)having an ethylenic unsaturated group per molecule, a diisocyanatecompound (e), a carboxylic acid (f) having two hydroxyl groups permolecule, and, as an optional component, a diol compound (g).
 8. A curedproduct of the photosensitive resin composition according to claim
 1. 9.A substrate comprising a layer composed of the cured product accordingto claim
 8. 10. An article comprising the substrate according to claim9.
 11. The photosensitive resin composition according to claim 2,wherein the curing agent (D) has a softening point or melting point ofnot less than 80° C.
 12. The photosensitive resin composition accordingto claim 2, wherein the curing agent (D) has a light transmittance at400 nm of not less than 10% in a 1 weight percent methyl ethyl ketonesolution.
 13. The photosensitive resin composition according to claim 2,wherein the resin (A) soluble in the aqueous alkaline solution is areaction product between an epoxy carboxylate compound obtained byreaction of an epoxy compound (a) having two or more epoxy groups permolecule with a monocarboxylic acid (b) having an ethylenic unsaturatedgroup per molecule, and a polybasic acid anhydride (c).
 14. Thephotosensitive resin composition according to claim 2, wherein the resin(A) soluble in the aqueous alkaline solution is a reaction productbetween an epoxy carboxylate compound obtained by reaction of an epoxycompound (d) having two epoxy groups per molecule with a monocarboxylicacid (b) having an ethylenic unsaturated group per molecule, adiisocyanate compound (e), a carboxylic acid (f) having two hydroxylgroups per molecule, and, as an optional component, a diol compound (g).15. A cured product of the photosensitive resin composition according toclaim
 2. 16. A substrate comprising a layer composed of the curedproduct according to claim
 15. 17. An article comprising the substrateaccording to claim
 16. 18. The photosensitive resin compositionaccording to claim 3, wherein the curing agent (D) has a softening pointor melting point of not less than 80° C.
 19. The photosensitive resincomposition according to claim 3, wherein the curing agent (D) has alight transmittance at 400 nm of not less than 10% in a 1 weight percentmethyl ethyl ketone solution.
 20. The photosensitive resin compositionaccording to claim 3, wherein the resin (A) soluble in the aqueousalkaline solution is a reaction product between an epoxy carboxylatecompound obtained by reaction of an epoxy compound (a) having two ormore epoxy groups per molecule with a monocarboxylic acid (b) having anethylenic unsaturated group per molecule, and a polybasic acid anhydride(c).
 21. The photosensitive resin composition according to claim 3,wherein the resin (A) soluble in the aqueous alkaline solution is areaction product between an epoxy carboxylate compound obtained byreaction of an epoxy compound (d) having two epoxy groups per moleculewith a monocarboxylic acid (b) having an ethylenic unsaturated group permolecule, a diisocyanate compound (e), a carboxylic acid (f) having twohydroxyl groups per molecule, and, as an optional component, a diolcompound (g).
 22. A cured product of the photosensitive resincomposition according to claim
 3. 23. A substrate comprising a layercomposed of the cured product according to claim
 22. 24. An articlecomprising the substrate according to claim 23.